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Re: [PATCH][rs6000] Support for PowerPC 750CL paired-single instructions
On Mon, Aug 27, 2007 at 05:06:25PM +0300, Revital1 Eres wrote:
> Trying to enable auto-vectorization for 750CL I realized I can not
> automatically decide whether to add -mpaired or -maltivec for the tests
> under the vect testsuite when 750CL is configure under powerpc*-*-*.
> This is because in vect.exp; a test is done to figure whether is it
> OK to compile for altivec. the test is done by simply compiling with
> -maltivec and check for no errors.
>
> return [check_no_compiler_messages powerpc_altivec_ok object {
> int dummy;
> } "-maltivec"]
>
> The problem is that this same configuration (powerpc-*-*) is also
> suitable for compiling with -mpaired; so we can not know automatically
> whether to add -mpaired or -maltivec to those tests just by compiling
> with those flags as they are both ok...
There's another check just below which checks for AltiVec hardware.
You could write similar checks for 750CL hardware. Then, if you have
one or the other you can test that one; if you have neither, fall back
to doing compile tests for AltiVec like we do now. How's that sound?
Alternatively, you can run the testsuite with a 750CL multilib when
you want to test the 750CL. That should issue an error compiling with
-maltivec, since the selected processor lacks AltiVec support. But
powerpc_paired_ok would still succeed.
--
Daniel Jacobowitz
CodeSourcery